Renamed "last_op" (last part of secure multi op instruction) to "last…
Created by: silabs-oysteink
…_sec_op".
Precursor to introducing "last_op" (last part of Zc* push/pop etc) in E40X to make merging easier.
SEC clean.
Signed-off-by: Oystein Knauserud Oystein.Knauserud@silabs.com